As the Search for the Universe’s Mysteries Expands, One Villanova Astronomer Turns Homeward

We live in an age where technology allows astronomers to observe objects at nearly incomprehensible distances from Earth. Distances so far, the time it takes their light to travel to our instruments is as old as the ever-expanding universe itself.

Growing alongside our capabilities is the interest of astronomers to search for new objects and new discoveries farther and farther away, shining a human light on them for the first time. It is a natural and important proclivity that deeply advances our understanding of the universe. But sometimes, in seeking treasure in someone else's backyard, we overlook what may be hiding in our own.

"There are always going to be more news stories about things that are further out, fainter and earlier in time," said Teddy Kareta, PhD, assistant professor of Astrophysics and Planetary Science at Villanova University. "I think it's because for a long time, people had this idea that the biggest and most important questions were outside the solar system.

"But, if you want to understand those things, you have to understand what happens within. And on a more emotional level, it's where we live. Every astronomer has their favorite stars or galaxies, and no one's ever going to go there. We've sent spacecraft to Neptune, Uranus and Pluto. In a couple of years, we could get to these places we have photographed. Yet, the kind of stuff that we still don't know about the solar system is so basic, it would shock people."

Addressing Questions That Hit Close To Home

Dr. Kareta was an undergraduate at UMass Amherst and just beginning to be interested in "nearby" astronomy when his own professor-solar system researcher Peter Schloerb, PhD-invited him to attend a lecture he was giving.

It was over the course of that hour-long presentation that Dr. Kareta was permanently drawn into near-Earth orbit.

"I came to realize how much there was to benefit from learning about the solar system, and how little anyone actually knows about it," he said.

"In some sense, it felt like the rug had been pulled out from underneath me, hearing somebody say, 'Actually, we don't really know how old the Earth is. Is it this number, or is it this 100-million-year-earlier number?' Or that we have an idea on how the Moon-that I've been seeing my entire life-formed, but the specific details on how and when, we don't know exactly. These are the kinds of small things you have to realize about the solar system to make you completely rethink the way that you live."

He continues on his philosophical rumination, and as a listener, one can't help but feel the same awe and disorientation he felt years ago listening to Dr. Schloerb's lecture.

How could it be that the same questions scientists like Sir Isaac Newton and Pierre-Simon Laplace asked centuries ago-ones that directly affect human life on Earth-could still be so mysterious?

Questions like what trajectory is the Earth on, and how long will it stay there? How long will the solar system be stable?

Even recent discoveries spark their own array of questions surrounding the basic nature of our solar system and its inhabitants. For instance, there has been tremendous progress in the last several decades in measuring the atmosphere of Venus-so much, that we are able to realize trace amounts of water exist, suggesting it once had quite a bit more.

"People have started wondering, was Venus habitable 700-million or a billion years ago? Well, that is around the time Earth was going through its climactic oscillations and was in 'snowball Earth' phase. So perhaps there is a period of time when Venus is warm, balmy and actually nicer than our ice cube in some ways.

"Venus is not some far-distant object-it's our neighbor; the beat-up old house up the road you come to find out may have once been a beautiful mansion. Doesn't it make you feel a little bit different about your neighborhood?"

These types of mysteries can hit so close to home that we can feel them.

"Scientists still disagree on the very basic question, 'where do the Earth's oceans come from?' Did Earth form with accumulated rocks that had some water in them, or was it delivered later? If later, by what-comets, or asteroids? We don't even really agree on which. That's the kind of magic that comes with this science-you can ask a question that sounds so simple until all the experts in the room start to rub their chins together simultaneously.

"Our solar system is full of both complex and basic problems that are completely unsolved."

Fleeting, But Incomparable, Research Opportunities

On July 1, 2025, the ATLAS survey telescope observed an object hurtling through the inner solar system at 140,000 miles per hour. In the days that followed, astronomers confirmed a thrilling hunch: it was a comet, and it originated outside of our solar system.

Named 3I/ATLAS-3I meaning just the third interstellar object observed in our solar system-the comet sparked a frenzy of data collection from scientists and piqued the interest of the public. Some months later, it would disappear forever.

Dr. Kareta was ready. A few years ago, in 2019, he was afforded the opportunity to study the year-long interlope of 2I/Borisov, the second interstellar object observed in our celestial home.

"That paper was written in three weeks," he said of that frenzied study. "With 3I/ATLAS, I think from the day our team got the data to when we submitted might have been 11 days. That's analyzing the data, having Zoom calls, making sure graduate students were sufficiently involved and writing the whole paper. It is so different than any other science field in that respect. If this thing's getting discovered this week, and we only have six weeks to study it before it leaves, other people should know what I figured out as soon as I figure it out, because it's never going to come back."

This is not unique to interstellar objects. As asteroids and comets complete their orbits around our Sun, they too offer only fleeting windows of study-sometimes, depending on that orbit, never to be seen again by the same sets of eyes currently on Earth. And when they do, the way we study them will assuredly be different. Dr. Kareta notes some objects we may see today were last photographed in Kodak film or sketched in journals.

"There is something romantic about studying the solar system in that sense," Dr. Kareta said. "You're on its schedule. It's like studying birds migrating-you've got one time a year. And if you want to study Halley's Comet, you wait for one human lifetime. That's just the timescale involved. Some people find that stressful, but I see it as an opportunity. And if you're training students, they might get to see something incredibly unique."

Hannah Bohlsen '26 CLAS is one of those students. An active undergraduate researcher, Bohlsen assisted Physics Professor Joey Neilsen, PhD, and Postdoctoral Researcher Riley Connors, PhD, with black hole research as a sophomore, and completed a REU (Research Experience for Undergraduates) program in spectroscopy the summer after her junior year in Utah.

Inspired by the work being done on 3I/ATLAS in Fall 2025, Bohlsen began looking at the carbon compounds in various comets throughout the solar system with Dr. Kareta. A comet's makeup is a glimpse into the environment where it was formed. By seeking trends in their carbon content and orbital information, Bohlsen says scientists can hopefully give better context to not only their origins, but those of these extreme interstellar outliers like 3I/ATLAS.

"It's very cool to be able to look at objects and address questions in our solar system that nobody has seen or done before," Bohlsen said.

The very nature of these types of studies invokes a sense of pride and unique ownership of a topic, especially among undergraduate researchers.

"They begin to realize the difference between them being an authority on something and being the expert is not necessarily years and years in the trenches," Dr. Kareta said. "Sometimes, it's just doing hard work when the opportunity arises.

"Sure, on one hand you get whatever data you get, and you will never get more. But at the same time, once that object leaves, nobody can beat you to it. It helps students work on their own timescale but also realize the gravity that comes with scientific research. They are contributing to their community in a specific way that only they can. As a mentor, it's incredible to be able to truthfully say, 'Chances are there is not a person in the world who knows more about this than you.'"

Bohlsen, who will be pursuing advanced degrees at the University of Virginia, was able to present this ongoing project in April at the NASA Delaware Space Grant Consortium. She was also awarded the Department of Astrophysics and Planetary Science's "Jason A. Cardelli Memorial Award for Undergraduate Research," for this and other scholarly contributions while at Villanova.

Though she intends to pursue a career in galactic archaeology, Bohlsen says "working in solar system astronomy has helped me piece together all I've learned before, and informed how I think about the future of the work I'm interested in." She also noted that she would be quick to highlight to peers and, further down the road, students, the importance of studying our celestial neighborhood.

After all, if it happens in our solar system, it happens in others, too. Even the ones billions of light years away.

"There is a kind of way that we talk about the solar system as if it's just our backyard," Dr. Kareta said. "But we are still making new discoveries-plants, animals-all the time here on Earth, and Earth is just one planet. It goes to show, just because it's our backyard doesn't mean it's not worth the investigation."